The demands made on electro casting resins could not be any more diverse. Different densities and viscosity levels on the one hand, extreme temperature variations, protection against overheating, impacts and chemicals on the other. Vehicles in particular are home nowadays to an ever increasing array of electrical and electronic components designed to enhance efficiency, safety, comfort and convenience. In addition, the development of electric vehicles is opening up whole new potential for power electronics.

The Grafenberg-based firm has developed a series of products entitled Raku-PUR 21-2120, 21-2161 and 21-2176 to provide effective protection for electric motors, relays, DC/DC converters, sensors and control systems. The two-component polyurethane-based casting materials are characterised by very good thermal conductivity (0.9 W/m·K) and temperature resistance (-50 °C to +130 °C), according to Rampf Giessharze.

Particularly in engine compartments with high levels of exhaust heat and inherent risk of overheating for sensitive components, the use of these PU systems can provide a solution. This product series complies with the requirements of fire protection class V0 in accordance with UL94 even with minimal coating thicknesses of just 2 mm. In developing the material, the company dispensed entirely with the use of flame retardants containing halogens. Rampf also paid particular attention to ensuring high application flexibility. By varying the hardener components used, different mixing viscosity levels of between 1,500 and 4,000 mPa·s can be achieved. The same versatility is offered in terms of pot life, which can be adjusted to the production capacity anywhere between 90 s at room temperature and 3.5 h at 50 °C.